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This particular inert gas was discovered by an astronomer observing a solar eclipse.

A couple of weeks ago I wrote a (tongue in cheek) post about a very inert gas, nitrogen. Silliness aside though, nitrogen is a bit, well boring. I mean, we’ve known about it for nearly 250 years, it makes up nearly 80% of our atmosphere and it mostly just sits around doing nothing. Even plants, who’ve mastered the spectacular trick of making solid stuff out of sunlight and carbon dioxide, can’t do much with it in its gaseous form (with a few exceptions).

We all learnt what ‘non-renewable’ means in school: it refers to something we’re using up faster than we can ever replace it. Almost anyone can tell you that crude oil is non-renewable. But the thing is, there are alternatives to crude oil. We can use bioethanol, biodiesel and their cousins to power vehicles and provide power. Bioethanol can act as a route to plastics, too. Scientists are also investigating the potential of algae to produce oil substitutes. These alternatives may (at the moment) be relatively expensive, and come with certain disadvantages, but they do exist.

We have no way to make helium. At least, no way to make it in significant quantities (it’s a by-product in nuclear reactors, but there we’re talking tiny amounts). And because it’s so light, when helium escapes into the atmosphere it tends to float, well, up. Ultimately, it escapes from our atmosphere and is lost. Every time you get fed up with that helium balloon that’s started to look a bit sorry for itself and stick a pin in it (perhaps taking a few seconds to do the squeaky-voice trick first) you’re wasting a little bit of a helium.

But so what? We could all live without helium balloons right? If we run out, balloons will just have to be the sinking kind. What’s the problem?

Liquid helium is used to cool the magnets in MRI machines.

The problem is that helium has a lot more uses than you might realise. Cool it to -269 oC – just 4 degrees warmer than absolute zero, the lowest termperature there is – and it turns into a liquid, and that liquid is very important stuff. It’s used to cool the superconducting magnets in MRI (magnetic resonance imaging) scanners in hospitals, which provide doctors with vital, non-invasive, information about what’s going on inside our bodies. MRI techniques have made diagnoses more accurate and allowed surgery to become far more precise. Nothing else (not even the lightest element, hydrogen) has a lower boiling point than helium, so nothing else is quite as good for this chilly job. Scientists are working hard on developing superconducting magnets that work at warmer temperatures, but this technology is still in its infancy.

There’s another technology called NMR (nuclear magnetic resonance) which chemists use all the time to help them identify unknown compounds. In fact, MRI was born out of NMR – they’re basically the same technique applied slightly differently – but the medical application was renamed because it was felt that patients wouldn’t understand that the ‘nuclear’ in NMR refers to the nuclei of atoms rather than nuclear energy or radiation, and would balk at the idea of a ‘nuclear’ treatment. Possibly imagining that they’d turn into the Hulk when they went into the scanner, who knows.

Since it works in essentially the same way, NMR also relies on superconducting magnets, also often cooled with liquid helium. Without NMR, whole swathes of chemical research, not to mention drug testing, would run into serious problems overnight.

The Earth’s helium supplies have largely originated from the very slow radioactive alpha decay that occurs in rocks, and it’s taken 4.7 billion years to build them up. Helium is often found sitting above reserves of natural oil and gas. In fact that’s exactly how the first helium reserve was discovered: when, in 1903, an oil drilling operation in Kansas produced a gas geyser that wouldn’t burn. It turned out that although helium is relatively rare in the Earth overall, it was concentrated in large quantities under the American Great Plains.

Show me the way to… The National Helium Reserve

Of course this meant that the United States quickly became the world’s leading supplier of helium. The US started stockpiling the gas during World War I, intending to use it in barrage balloons and later in airships. Helium, unlike the other lighter-than-air gas hydrogen, doesn’t burn. This made things filled with helium safer to handle and, of course, more difficult to shoot down or sabotage.

In 1925 the US government set up the National Helium Reserve in Amarillo, Texas. In 1927 the Helium Control Act came into force, which banned the export of the gas. At that point, the USA was the only country producing helium, so they had a complete monopoly (personally, I’d quite like to see a Monopoly board with ‘helium reserves’ on it, wouldn’t you?). And that’s why the Hindenburg, like all German Zeppelins, both famously and tragically had to use hydrogen as its lift gas.

Helium use dropped after World War II, but the reserve was expanded in the 1950s to supply liquid helium as a coolant to create hydrogen/oxygen rocket fuel during the Space Race and the Cold War. The US continued to stockpile helium until 1995. At which point, the reserve was $1.4 billion in debt. The government of the time pondered this and ended up passing the Helium Privatization Act of 1996, directing the United States Department of the Interior to empty the reserve and sell it off at a fixed rate to pay off the cost.

Right now, anyone can buy cheap helium in supermarkets and high street shops.

As a result cheap helium flooded the market and its price stayed fairly static for a number of years, although the price for very pure helium has recently risen sharply. This sell-off is why we think of helium as a cheap gas; the sort of thing you can cheerfully fill a balloon with and then throw away. Pop down to a large supermarket or your local high street and you might even be able to buy a canister of helium in the party section relatively cheaply.

The problem is that this situation isn’t going to last. The US reserves have been dramatically depleted, and at one point were expected to run out completely in 2018, although other reserves have since been discovered and other countries have set up extraction plants. It is also possible to extract helium from air by distillation, but it’s expensive – some 10,000 times more expensive. None of these alternatives are expected to really ease the shortage; they’ll just delay it by a few years.

So are helium party balloons truly an irresponsible waste of a precious resource? Well… the helium that’s used in balloons is fairly impure, about 98% helium (mixed with, guess what? Yep, we’re back to nitrogen again!) whereas the helium that’s needed for MRI and the like is what’s called ‘grade A’ helium, which is something like 99.997% pure, depending on whom you ask. Of course you can purify the low-grade helium to get the purer kind but this costs money, which is why grade A helium is so much more expensive.

The National Balloon Association (‘the voice of the balloon industry’ – you can’t help wondering whether that’s a very high-pitched voice, can you?) argues that balloons only account for 5-7% of helium use and that the helium that goes into balloons – which they prefer to call ‘balloon gas’ because of its impurities – is mainly recycled from from the gas that’s used in the medical industry, or is a by-product of supplying pure, liquid helium, and therefore using it in balloons isn’t really a problem.

Dr Peter Wothers argues that helium balloons should be banned.

On the other hand, more than one eminent physics professor has spoken out on the subject of helium wastage. It costs about 30-50p to fill a helium balloon, but Professor Robert Richardson of Cornell University argued (before his death in 2013) that a helium party balloon should cost £75 to more accurately reflect the true scarcity value of the gas. Dr Peter Wothers of Cambridge University has called for an outright ban of them, saying that in 50 years’ time our children will be amazed that we ever used such a precious material to fill balloons.

Is it time to call for a helium balloon boycott? Perhaps, although it will probably take more than one or two scientifically-minded consumers refusing to buy them before we see any difference. Realistically, the price will sky-rocket in the next few years and, as Peter Wothers suggests, filling balloons with helium will become a ridiculous notion because it’s far too expensive.

Will images like this make no sense in the future?

It’s strange to think though, that in maybe 50 years or so the idea of a floating balloon might simply disappear. Just think of all the artwork and drawings that will no longer make sense.

Perhaps this quotation by the late Sir Terry Pratchett is even more relevant than it first appears:

“There are times in life when people must know when not to let go. Balloons are designed to teach small children this.”

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Today I’m writing about a potentially dangerous, but surprisingly rarely discussed, substance. It’s a gas at room temperature, with a molecular mass of 28. It sits next to oxygen in the periodic table, but these two could not be more different. When it was discovered by Daniel Rutherford in 1972 he named it ‘noxious air’. Other scientists called it ‘burnt air’, ‘mephitic air’, and ‘azote’ – from the Greek word meaning lifeless – because animals died when they were exposed to it. Today we call it nitrogen.

Let me tell you more. It’s an industrial chemical which is used to make fertilisers and explosives, and to fill tyres. Does that sound like something that you should be exposed to on a daily basis?

Nitrogen is used to fill aeroplane and car tyres.

Well I’ve got news for you, you are. Nitrogen is in the air around us. That’s right, this gas which, let me reiterate, was discovered when it was found to kill small animals, is all around us. The concentration of it is fairly stable now, but it has increased dramatically in Earth’s past.

A nitrogen molecule. Not actual size.

Breathing air with more than about 0.8 bar partial pressure will make you really ill or even kill you and yet, pure nitrogen is regularly used to package our foods. Those salad bags you thought were so fresh and healthy? Full of pure nitrogen. That nitrogen is obtained by a process known as fractional distillation. Petrol, diesel and bitumen – the stuff used to cover our roads – are produced by exactly the same method.

Nitrogen is invisible, tasteless and odourless, and companies don’t have to label it on their packaging. Some of the more reputable manufacturers do state that their food is ‘packaged in a protective atmosphere’, but since there is no regulation to force companies to include this label, its absence is no guarantee. You could be eating nitrogen-drenched lettuce right now, and you’d have no idea. And for those salad-dodgers out there breathing a sigh of relief, crisps (chips, for my American readers) are also packaged in this stuff.

Nitrogen is often used in over-priced food preparation.

It gets worse. When it’s cooled nitrogen becomes a liquid, and this form is also used in food preparation. Some chefs have famously used it to make gourmet ice-cream. But in its liquid form nitrogen is even more dangerous. It’s extremely volatile. Exposure to liquid nitrogen causes severe and painful burns which can leave permanent scars. People who need to handle it should wear thick, industrial-strength gloves and eye protection. It’s so dangerous that one Australian liquor authority recently ordered bars to stop serving drinks containing liquid nitrogen after a patron became seriously ill.

Surely we should be asking the question: should something this harmful REALLY be involved in food preparation at all, anywhere in the world?

The Food Doll. She knows about this stuff.

Health food campaigners and ‘wellness warriors’ are increasingly setting their sites on this new menace. In an interview, ‘Food Doll’ Eyna Noscience said, “During my research into this stuff I found out that food companies sometimes mix it with carbon dioxide, and we all know that’s killing the ozone layer. We should all be campaigning for better labelling.”

She went on to add: “It’s a pnictogen. I don’t know what that means, but it sounds suspiciously like carcinogen to me. Nothing that unpronounceable can be good for you, right? I always say, if you can’t read it, you shouldn’t be eating it. Or breathing it.”

Despite clearly knowing nothing whatsoever about anything, it’s possible that Eyna Noscience has a point. Perhaps consumers should have the choice over whether they want to buy products saturated with nitrogen? The organisation Cease the Ugly Nitrogen Terror certainly think so. They recently held a peaceful demonstration outside a well-known supermarket in London. Several of their supporters, who were holding placards bearing the initials of the organisation, were arrested for allegedly “offensive slogans”. Clearly yet another example of the food industry having far too much power.

What do you think? Should nitrogen be banned from foods? Leave your comments below.

GNU Terry Pratchett.

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Note: now, in case it’s not entirely obvious, this post is a joke (I say this because some people have asked me, believe it or not). But truth, as they say, is stranger than fiction. After I wrote this I found out that the ‘Food Babe’, aka Vani Hari, had actually written a post (she has since deleted it, but the internet is great for making it difficult to hide such things) in which she demonstrated a fabulous misunderstanding of chemistry and physics. In particular (from here, 6th paragraph):

“The air you are breathing on an airplane is recycled from directly outside of your window. That means you are breathing everything that the airplanes gives off and is flying through. The air that is pumped in isn’t pure oxygen either, it’s mixed with nitrogen, sometimes almost at 50%. To pump a greater amount of oxygen in costs money in terms of fuel and the airlines know this! The nitrogen may affect the times and dosages of medications, make you feel bloated and cause your ankles and joints swell.”

I don’t know about everyone else, but personally I’d be a bit worried about a 50% oxygen atmosphere, particularly in an aeroplane. Let’s just hope she’s wrong, eh?

But here’s the question: have you been paying attention? Well, have you? Time to find out with The Chronicle Flask’s festive quiz! I haven’t figured out how to make this interactive. You’ll have to, I don’t know, use a pen and paper or something.

Question 1)
Which scientist invented a chemical test that can be used to coat the inside of baubles with silver?
a) Bernhard Tollens
b) Karl Möbius
c) Emil Erlenmeyer

Question 2)
Reindeer eat moss which contains arachidonic acid… but why is that beneficial to them?
a) a laxative
b) an anti-freeze
c) a spider repellant

Question 7)Where are you most likely to find this molecule at this time of year?
a) in a roast beef joint
b) in the wrapping paper
c) in the christmas cake

Question 8)
Let it snow, let it snow, let it snow… but which fact about (pure) water is true?
a) It glows when exposed to ultraviolet light
b) It expands as it freezes
c) It’s a good conductor of electricity

Question 9)
Where are you likely to find this molecule on New Year’s Eve?
a) in a champagne bottle
b) in the party poppers
c) in the ‘first foot’ coal

Question 10)
Who doesn’t love a firework or two on New Years Eve? But which element is most commonly used to produce the colour green?
a) magnesium
b) sodium
c) barium

So how did you do?
Less than 4: D, for deuterium. It’s heavy hydrogen and it’s used to slow things down. Enough said.
4-6: You get a C, by which I mean carbon. Have another slice of coal.
7-8: You’ve clearly been paying attention. B for boring, I mean boron.
9-10: Au-ren’t you clever? Chemistry champion!

Anyway, if you’re still with me and haven’t dashed off to immediately download some of these little gems, the most recent episode is about weights and measures and how we’ve standardised them over the years. In particular the kilogram, which is the last physical standard in use, although possibly not for long (listen to the podcast).

So what are the scales made of…?

This got me thinking about atoms and, in particular, how we decide their mass. This matters you see, because the mass of atoms tells us chemists how much stuff to use. If I want a saline solution with a particular concentration, all I need do is look up the numbers on the periodic table, weigh out the appropriate amount of salt and dilute it with the appropriate amount of water. And if you’re a patient who needs a saline drip, you’d better hope I did it correctly.

Anyway, if you remember your periodic table (which of course you do, but just in case, here’s a picture) all the elements come with two numbers.

One of these numbers is the atomic number, which is the number of protons in the nucleus of each atom of the element. Conveniently, nature has managed to produce an atomic nucleus for each number between 1 and, at last count, 118 and if you ‘read’ the periodic table from left to right, top to bottom, you’ll see the numbers go up one at a time.

The other number, relative atomic mass, is a bit less tidy. It still goes up as you go along the periodic table, but in less regular jumps of roughly between one and three. Without going into lots of detail, relative atomic mass is standardised against 1⁄12 the mass of carbon-12. Which begs the question, why? The more mathematically aware will have clocked that 1⁄12 of 12 is, well, 1. So why don’t we compare all the elements to hydrogen, which actually has a mass of 1? Or if that’s infeasible for some reason why not, I don’t know, choose 1⁄9 of beryllium-9, or 1⁄28 of silicon-28?

Well actually, almost exactly 200 years ago now, atomic mass (called atomic weight, at the time) was originally compared to hydrogen, and it was thought that all elements would have masses which were exact multiples of hydrogen’s.

The problem with this was that as measuring techniques became more sophisticated it became clear that some elements were inconveniently failing to follow the rule. In fact, some were downright contrary, like chlorine which appeared to have a mass which wasn’t even a whole number.

This was, at least partially, sorted out in 1932 when James Chadwick proved the existence of neutrons. The existence of isotopes had already been suggested, but this finally cleared up what the pesky things actually were. It turns out some atoms are fatter than others, having one or two more uncharged particles in their nuclei. This doesn’t change what atom they are – they still have the same number of protons – but it does make them a bit heavier. Take a sample of pure chlorine, for example, and you find that roughly three quarters of the atoms in it have a mass of 35, whereas the other quarter have a mass of 37. These are the isotopes of chlorine: imaginatively named chlorine-35 and chlorine-37. Work out the weighted average of the two and you get 35.5, which is the number you see on periodic tables.

In the mid-20th century something of a minor squabble between chemists and physicists broke out (chemists and physicists often squabble: they’re a bit like the English and the French: they like to visit each other but only so that they can moan about how annoying the other lot are and how badly they do everything). By this time had been a switch from using hydrogen (the lightest element) to oxygen as the standard to which other elemental masses were compared. This was mainly for the convenience of chemical analysis: oxygen combines with a lot of things to make straightforward oxides, whereas hydrides are less common and trickier to work with. Plus, large quantities of hydrogen gas are a bit (in the sense of an elephant being a bit heavy, or cyanide being a bit poisonous) of an explosion risk. Oxygen causes other things to burn jolly nicely, but isn’t actually flammable itself. If you can manage to keep it away from other flammable stuff it’s a far safer option.

The problem was that chemists were using a mass scale based on assigning the number 16 to a natural mixture of oxygen (which contains mostly oxygen-16, with little bits of oxygen-17 and oxygen-18). Physicists, on the other hand, had instead assigned the number 16 to the isotope oxygen-16, which they had isolated using the technique of mass spectrometry.

Physicist Josef Mattauch

You may think the physicists’ method sounds more logical, but the chemists’ reasoning was that in naturally-occurring compounds there would be a mixture of isotopes, so it made sense to use a number based on that mixture since you never actually encounter one atom on its own. Either way, the result was differences in the numbers, admittedly some way down the decimal places, but none the less a difference. Of course it was possible to convert between the two, but at the time scientists were fiddling with such tricksy things as nuclear energy and, of course, bombs. Even a tiny discrepancy in the nth decimal place was potentially catastrophic. Something had to be done.

Chemist Edward Wichers

In 1961 a compromise was agreed, thanks largely to the combined efforts of the physicist Josef Mattauch and the chemist Edward Wichers, who set about persuading their respective groups to be reasonable and play nicely with each other.

The result was that carbon-12 was assigned a mass of exactly 12 and the relative atomic mass scale became based on that. The choice of carbon was, to an extent, somewhat arbitrary. It suited the physicists, who were already using carbon as a standard for mass spectrometry. It fell in between the two previous values (1 for hydrogen and 16 for oxygen), which meant it wouldn’t throw every existing piece of work out by too much. In particular, chemists weren’t keen on switching to the physicists’ method of 1⁄16 of the oxygen-16 isotope, because it would change their numbers quite significantly. Switching to 1⁄12 of carbon-12 meant, surprisingly, a smaller change. Carbon is also, of course, a naturally abundant element and it was easy to get samples of pure carbon.

And that, as they say, is that. The carbon-12 scale is still used today, over 50 years later, and it’s not going anywhere. Hydrogen is officially 1⁄12 the mass of carbon-12, and we use carbon-12 because, basically, it was the only option the chemists and physicists would agree on. Hey, it’s as good a reason as any.

I was thinking about phenol the other day. “Very interesting,” I hear you say, “now if you don’t mind I’ve got a fascinating patch of drying paint I need to keep an eye on.” But wait! Bear with me. Phenol is a very interesting molecule. It’s history has a little something for everyone, from lawyers to doctors to advertising copywriters. There are gruesome tales from history, legal wrangles, and even a warning about the dangers of believing everything you read on the internet. So drag yourself away from the eggshell white, find yourself a comfy seat and I’ll begin.

Phenol: a simple molecule with a complicated history.

Phenol is a simple molecule, consisting of a single -OH group attached to what chemists call a benzene ring (the structure of which was, so legend has it, finally determined after the German chemist August Kekulé dreamt of a snake eating its own tail).

You may think you’ve never heard of phenol, less still used it, but chances are you’ve come across the term ‘carbolic soap‘ somewhere. Phenol’s other name is carbolic acid, and it’s the main ingredient in carbolic soap, a mildly disinfectant cleaning agent that used to be a common household product in both Britain and America (in the form of Lifebuoy), was widely used in English state schools up until at least the 1970s, and is distributed to disaster victims for routine hygiene by the Red Cross to this day.

Carbolic soap isn’t so common these days since it has a tendency to irritate the skin and far gentler alternatives are available, although you can still find it in specialist outlets and apparently it’s quite popular in the Caribbean.

Friedlieb Ferdinand Runge

But back to phenol itself. It was discovered in 1834 when it was extracted from coal tar – a by-product of the coal industry – by the chemist Friedlieb Ferdinand Runge, also famous for identifying caffeine.

Joseph Lister

Despite his rather glorious name, Runge is not the best-remembered scientist associated with phenol. That honour almost certainly goes to Joseph Lister who, in the late 19th century, pioneered the technique of antiseptic surgery. It may seem difficult to believe today, but back then surgeons weren’t required to wash their hands before treating patients, and even took pride in the accumulated stains on their surgical gowns. Until Lister’s use of phenol (or carbolic acid), people were more likely to die from infection following the treatment than from the original injury itself. Lister started using phenol to sterilise surgical instruments and wounds and after seeing his results others soon followed, completely changing surgery as we know it today.

In case you’re wondering, Lister had nothing directly to do with the invention of the (phenol-free) mouthwash product that bears his name. It was, however, named after him in honour of his work. Interestingly, Listerine was first marketed as a surgical antiseptic, then a floor cleaner and a cure for gonorrhoea, before it eventually found success as a solution for bad breath.

I mentioned lawyers earlier, and that’s because phenol was instrumental in one of the first examples of contract law: Carlill v Carbolic Smoke Ball Company [1892]. It wasthe main ingredient of the Carbolic Smoke Ball, an ineffective piece of medical quackery marketed in London in the 19th century as protecting the user against influenza and other ailments. The manufacturer advertised that buyers who found it did not work would be awarded £100.

The Carbolic Smoke Ball Company thought this was nothing more than an inspired piece of advertising, and tried to argue that it was “mere puff” that no reasonable person would take literally. The judge rejected their claims, ruled that the advert made an clear promise, and ordered the company to pay £100 to the unfortunate flu-suffering customer Louisa Carlill. To this day, this case is often cited as an example of the basic principles of contract and how they relate to every day life.

St. Maximilian Kolbe

Phenol also has a darker past, injections of it having been used as a means of execution. In particular, in World War II the Nazis used it in the euthanasia program, Action T4. Phenol was inexpensive, easy to make and fast-acting, and so quickly became the injectable toxin of choice. Famously, the Polish Catholic priest St. Maximilian Kolbe volunteered to undergo three weeks of starvation and dehydration in the place of another inmate and was ultimately executed by phenol injection. Kolbe was canonized on 10 October 1982 by Pope John Paul II; he is the patron saint of drug addicts.

Anyone who’s ever used phenol has probably experienced a phenol burn at some point. It doesn’t always hurt immediately but it slowly starts to burn after a little while, leaving white marks that ultimately turn red and slough off leaving brown-stained skin behind. It is, I should stress, not to be messed with – absorption of phenol through skin can result in phenol toxicity, and if left on the skin it can lead to cell death and gangrene. Even a tiny not-even-remotely-lethal spot is really quite painful. I can’t begin to imagine what death from phenol injection must have been like.

Let’s end on a slightly lighter note. Have you got a bottle of TCP in your medicine cabinet? Many have fallen into the trap of believing that its initials relate directly to its ingredients, and specifically 2,4,6-trichlorophenol. In fact, a number of chemistry textbooks have stated this as hard, cold fact, as did a number of other online sources.

Not so, TCP originally contained trichlorophenylmethyliodosalicyl (not the same thing, and actually some have even wondered if this is truly a compound), but even that was replaced by other active ingredients in the 1950s. These days TCP contains a dilute solution of phenol (about 0.175% w/v) and halogenated phenols (0.68 w/v). So after all that, it does have phenol in it, but it’s not clear whether ‘halogenated phenols’ includes 2,4,6-trichlorophenol.

For a long time many, many websites stated that TCP contained trichlorophenylmethyliodosalicyl, probably traceable back to an earlier Wikipedia article (Wikipedia’s information has since been updated). As Jim Clark points out on his excellent Chemguide website, “The internet is a potentially dangerous tool. One single bit of misinformation can get multiplied over huge numbers of web sites”.

Next week on September 12th some extremely important prizes are about to be awarded that will undoubtedly rock the scientific community. Yes indeed, it’s that time again: the annual Ig Nobel prize award ceremony.

I first met the Igs about 15 years ago when I went to a conference in Seattle (yes I’m that old). The talk was a popular one, the Igs being a bit of light relief from all the serious science being discussed. That year there were awards for the development of a suit of armor impervious to grizzly bears, a study on the relationship between height, foot size and penile length (admit it, you’ve always wanted to know) and Jacques Benveniste of France, for his homeopathic ‘discovery’ that not only does water have memory, but that the information can be transmitted over telephone lines and the Internet (hmm).

So what are they, exactly? Some describe them as parodies of the official Nobel prizes. Home of the Igs AIR, the Annals of Improbable Research, describes them as awards for research that makes people laugh, and then think. Sometimes, as in the case of Benveniste, an Ig is awarded to someone for their, shall we say, excessively creative application of scientific ideas. More often these days they are awarded to scientists who’ve worked on something rather weird and wonderful, but which actually turns out to have some interesting applications.

So, since this is a chemistry blog, what have the last few Ig Nobel Chemistry prizes been awarded for?

2012: Johan Pettersson, for solving the puzzle of why, in certain houses in the town of Anderslöv, Sweden, people’s hair turned green.
A great story, this: Several formerly blonde inhabitants of Anderslöv in southern Sweden suddenly acquired new green hairdos. Initially suspicion fell to the water supply, specifically copper contamination, since copper is known to dye hair green. But the problem was only affecting certain households. Testing revealed that copper levels were normal in the water supply itself, however when the water sat in the pipes in some recently-built houses overnight the copper levels rocketed. Why? Copper pipes in the new houses weren’t coated on the inside, so copper was leaching into the water. Residents who’d rather not have green hair have been told to wash their hair in cold water.

2011:Makoto Imai, Naoki Urushihata, Hideki Tanemura, Yukinobu Tajima, Hideaki Goto, Koichiro Mizoguchi and Junichi Murakami, for determining the ideal density of airborne wasabi to awaken sleeping people in case of a fire or other emergency, and for applying this knowledge to invent the wasabi alarm.
In this case the title says it all. As anyone that’s ever eaten a lump of that green stuff that comes with sushi knows, if wasabi gets into your nasal passages you know about it. The researchers worked out exactly how much wasabi would need to be in the air for it to be intolerable, and then developed and patented an alarm system that releases that concentration of wasabi in case of emergency. Well, at least it won’t wake up the neighbours.

2010: Eric Adams, Scott Socolofsky, Stephen Masutani, and BP, for disproving the old belief that oil and water don’t mix.
A silly title with a serious motive, oil spills being something of a big deal. A team of scientists conducted controlled discharges of oil and water in the Norwegian sea at a depth of 844 meters and demonstrated that most oil from a spill in the deep ocean would in fact mix with water, rather than rise directly to the surface. The decision to award the prize jointly to BP, given the recent Deepwater Horizon incident, was particularly cutting.

2009:Javier Morales, Miguel Apátiga, and Victor M. Castaño, for creating diamonds from liquid — specifically from tequila.
This might just be my favourite. It sounds ridiculous, and yet they published a serious paper. Scientists have long used various solvent mixtures to grow thin diamond films, and the researchers in this case were experimenting with mixtures of ethanol (‘drinking’ alcohol) and water. They noticed that the mixture that produced the best results had a similar composition to tequila, and so decided to experiment with the alcoholic beverage. It turned out that some types of tequila really did have exactly the right mixture of carbon, hydrogen and oxygen to promote growth of the films.

2008:Sharee A. Umpierre, Joseph A. Hill, Deborah J. Anderson and Harvard Medical School, for discovering that Coca-Cola is an effective spermicide, and to Chuang-Ye Hong, C.C. Shieh, P. Wu, and B.N. Chiang for discovering that it is not.
The mind boggles, doesn’t it? There are many myths associated with pregnancy, and what does and doesn’t prevent it. No one would seriously recommend Coca-Cola as a contraceptive. However the first set of researchers decided to look into the question in a little more depth. They tested small samples of sperm with different types of Coca-Cola and found that they did, indeed, kill some sperm. However their results couldn’t be reproduced by the second set of scientists, who concluded that if Coke did have a spermicidal effect it was weak – little different to their control sample. A Coca-Cola spokesperson responded that “we do not promote any of our products for any medical use”. Glad they cleared that up.

You can see the full list of Ig Nobel prize winners here. The 2013 Ig Nobel prizes will be announced on Thursday September 12, 2013. You can join in on Twitter with the hashtag #IgNobel, and there’s also a webcast at 5:30pm EDT, which if my calculations are correct is 10:30am over here in the UK. I wonder what will be recognised this year…

Let’s talk about element number 79. It’s one of the oldest known elements, used for quite literally thousands of years. It’s constantly at the heart of conflicts and politics. Poets have waxed lyrical about it, authors have written about it, economists and prospectors have hinged their livelihoods on it. And, of course, chemists have studied it.

As an element it’s unusual. It’s a metal, but instead of the boring silvery-grey of most metals it glows a warm yellow. It’s also one of the most unreactive elements, and yet has found use a catalyst – speeding up chemical reactions that otherwise would be too slow to be useful. It’s rare, making up only about 0.004 parts per million of the Earth’s crust, and yet its annual production is surprisingly high: 2700 tonnes in 2012. Its density makes it heavy – weighing over nineteen times more than the same volume of water – but it’s also relatively soft, so soft that it’s possible to scratch a pure piece with your fingernail (in theory, and if you have fairly robust fingernails).

The history of gold is fascinating. You could easily write a whole book about it. In fact, someone has. I won’t attempt anything so ambitious, but it does have some very interesting chemical stories associated with it.

Because of its unreactivity, gold is one of the relatively few elements that’s found uncombined in nature. In other words, you can pick up a piece of pure gold from the ground or, more likely, out of a river bed. Thanks to this property it’s very probably the first metal that humans as a species interacted with. It’s too soft to be much use as a tool, so its earliest uses were almost certainly ornamental. Decorations and jewellery had value and could be traded for other things, and ultimately (skipping over a chunk of history and early economics) this led to currency.

And so it was that early alchemists, some two thousand years ago, became obsessed with the idea of a quick buck. Could other metals be turned into gold? They searched long and hard for the mythical philosopher’s stone (like in Harry Potter, only not exactly) which could turn base metals into gold or silver. Of course they never found it, because it doesn’t exist. It’s not possible to change one element into another during a chemical reaction. This is because what defines an element is the number of protons in its nucleus, and chemistry is all about the electrons. Chemical processes don’t touch protons, which are hidden away in the nuclei of atoms.

But where there’s a will there’s almost always a way. Two millennia after alchemists were hunting for a magical stone, the chemist Glenn Seaborg managed to transmute a minute quantity of lead, via bismuth, into gold by bombarding it with high-energy particles. Apparently, these days particle accelerators ‘routinely’ transmute elements, albeit only a few atoms at a time.

The trouble is, this method costs a fortune – way, way more than the value of any gold produced. Gold, after all, is ‘only’ worth about a thousand pounds for a troy ounce (31 grams). Particle accelerators cost billions of pounds to build, and yet more in running costs. If you really want gold so desperately, these days there may be more mileage in harvesting it from defunct bits of electronic equipment.

Or just ask people to send you their old jewellery through the post in exchange for cash. Even Tesco have got into that game now. Through the post! Honestly, people fear putting a tenner in a birthday card but gold jewellery in a paper bag? No problem.

But anyway, back to gold’s reactivity, or rather lack of it. Gold isn’t the most unreactive element (depending on how you’re defining reactivity, that honour probably goes to iridium) but it’s up there. Or perhaps I should say down there. It keeps its shiny good looks even when it’s regularly in contact with warm, damp, salty, slightly acidic skin, which is quite handy from the jewellery and money point of view.

But there is one thing gold reacts with: aqua regia. Aqua regia is a mixture of nitric and hydrochloric acid and ancient alchemists gave it its name – which literally means ‘royal water’ – because it dissolves the ‘royal’ metal, gold. It’s pretty cool stuff, in a slightly scary way. Freshly-prepared it’s colourless, but quickly turns into a fuming, reddish solution. It doesn’t keep – the hydrochloric and nitric acids effectively attack each other in a series of chemical reactions which ultimately result in the production of nitrogen dioxide, accounting for the orange colour and nasty fumes. The fire diamond (remember those?) for aqua regia has a 3 in the blue box, putting it on a nastiness par with pure chlorine, ammonia and, funnily enough, oxalic acid (the stuff in rhubarb). It also has ‘ox’ in the white box, telling us it’s a powerful oxidising agent, which means it’s effectively an electron thief.

All atoms contain electrons but they can, and frequently do, lose or gain them during the course of chemical reactions. Acids in general are often quite good at pinching electrons from metals, but aqua regia is particularly good at it, and especially with gold. Much, much better than either nitric acid or hydrochloric acid on their own because, in fact, the two work together, as a sort of two-man gang of acid muggers. When metal atoms lose electrons they become ions, and ions dissolve very nicely in water. Hence, aqua regia’s fantastic property of being able to dissolve gold.

Which leads me to a really great story. During World War II it was illegal to take gold out of Germany, but two Nobel laureates – Max von Laue, who strongly opposed the National Socialists, and James Franck, who was Jewish – discretely sent their 23-karat, solid gold Nobel prize medals to Niels Bohr’s Institute of Theoretical Physics in Copenhagen for protection. All well and good, until the Nazis invaded Denmark in 1940. Now, unfortunately, the evidence of von Laue and Franck’s crime was sitting on a shelf in a lab, just waiting to be found. This was serious: if the Gestapo found the gold medals they would persecute von Laue and Franck, and probably take the opportunity to make things very unpleasant for Bohr as well, particularly since his institute had protected and supported Jewish scientists for years.

What to do? At the time a Hungarian chemist called George de Hevesy was working at the institute, and it was he that had the bright idea of dissolving the medals in aqua regia.

It would have taken ages, because although aqua regia dissolves gold, it doesn’t do it quickly, and these were chunky objects. He must have been anxiously looking over his shoulder the whole time. But he managed it, and eventually ended up with a flask of orange liquid that he stashed on a high shelf. The Nazis searched the building but didn’t realise what the flask was, so they left it. Iit stayed there undisturbed for years, in fact until after the war was over. At which time, de Hevesy precipitated the gold back out and sent the metal back to the Swedish Academy, who recast the prizes and re-presented them to Franck and von Laue.

So there we have it, you can’t turn lead into gold (at least, not without a particle accelerator) but, if you know what you’re doing, you might just be able to turn a flask of orange liquid into two solid gold Nobel prize medals!

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The title of this post comes from a poem by the British poet, Thomas Hood, 1799-1845. Here it is in full:

Gold!
Gold! Gold! Gold! Gold!
Bright and yellow, hard and cold
Molten, graven, hammered and rolled,
Heavy to get and light to hold,
Hoarded, bartered, bought and sold,
Stolen, borrowed, squandered, doled,
Spurned by young, but hung by old
To the verge of a church yard mold;
Price of many a crime untold.
Gold! Gold! Gold! Gold!
Good or bad a thousand fold!
How widely it agencies vary,
To save – to ruin – to curse – to bless –
As even its minted coins express :
Now stamped with the image of Queen Bess,
And now of a bloody Mary.